Value of Computerized 3D Shape Analysis in Differentiating Encapsulated from Invasive Thymomas

Jong Hyuk Lee; Chang Min Park; Sang Joon Park; Jae Seok Bae; Sang Min Lee; Jin Mo Goo

doi:10.1371/journal.pone.0126175

Value of Computerized 3D Shape Analysis in Differentiating Encapsulated from Invasive Thymomas

PLoS One. 2015 May 4;10(5):e0126175. doi: 10.1371/journal.pone.0126175. eCollection 2015.

Authors

Jong Hyuk Lee¹, Chang Min Park², Sang Joon Park², Jae Seok Bae¹, Sang Min Lee¹, Jin Mo Goo²

Affiliations

¹ Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
² Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea; Cancer Research Institute, Seoul National University, Seoul, Korea.

Abstract

Objectives: To retrospectively investigate the added value of quantitative 3D shape analysis in differentiating encapsulated from invasive thymomas.

Materials and methods: From February 2002 to October 2013, 53 patients (25 men and 28 women; mean age, 53.94 ± 13.13 years) with 53 pathologically-confirmed thymomas underwent preoperative chest CT scans (slice thicknesses ≤ 2.5 mm). Twenty-three tumors were encapsulated thymomas and 30 were invasive thymomas. Their clinical and CT characteristics were evaluated. In addition, each thymoma was manually-segmented from surrounding structures, and their 3D shape features were assessed using an in-house developed software program. To evaluate the added value of 3D shape features in differentiating encapsulated from invasive thymomas, logistic regression analysis and receiver-operating characteristics curve (ROC) analysis were performed.

Results: Significant differences were observed between encapsulated and invasive thymomas, in terms of cystic changes (p=0.004), sphericity (p=0.016), and discrete compactness (p=0.001). Subsequent binary logistic regression analysis revealed that absence of cystic change (adjusted odds ratio (OR) = 6.636; p=0.015) and higher discrete compactness (OR = 77.775; p=0.012) were significant differentiators of encapsulated from invasive thymomas. ROC analyses revealed that the addition of 3D shape analysis to clinical and CT features (AUC, 0.955; 95% CI, 0.935-0.975) provided significantly higher performance in differentiating encapsulated from invasive thymomas than clinical and CT features (AUC, 0.666; 95% CI, 0.626-0.707) (p<0.001).

Conclusion: Addition of 3D shape analysis, particularly discrete compactness, can improve differentiation of encapsulated thymomas from invasive thymomas.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Female
Humans
Male
Middle Aged
Retrospective Studies
Thymoma / classification
Thymoma / diagnostic imaging*
Tomography, X-Ray Computed

Grants and funding

This study has received funding by the Research of the Korean Foundation for Cancer Research (grant number: CB-2011-02-01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.